- Number 423 |
- September 29, 2014
Heat drives classical phase transitions—think solid, liquid, and gas—but much stranger things can happen when the temperature drops. When phase transitions occur at the coldest temperatures imaginable, where quantum mechanics reigns, subtle fluctuations can dramatically transform a material.
Scientists from DOE’s Brookhaven National Laboratory and Stony Brook University have now explored this absolute-zero landscape and probed these quantum phase transitions with unprecedented precision.
“Under these cold conditions, the electronic, magnetic, and thermodynamic performance of metallic materials is defined by these elusive quantum fluctuations,” said study coauthor Meigan Aronson, a physicist at Brookhaven Lab and professor at Stony Brook. “For the first time, we have a picture of one of the most fundamental electron states without ambient heat obscuring or complicating those properties.”
Scientists are a step closer to building an intense electron beam source without a laser. Using the High-Brightness Electron Source Lab at DOE’s Fermi National Accelerator Laboratory, a team led by scientist Luigi Faillace of RadiaBeam Technologies is testing a carbon nanotube cathode — about the size of a nickel — that completely eliminates the need for a room-sized laser system. Tests with the nanotube cathode have produced beam currents a thousand to a million times greater than the one generated with a large, pricey laser system.
The technology has extensive applications in medical equipment and national security, since an electron beam is a critical component in generating X-rays.
Researchers at the DOE's Argonne National Laboratory have created a small scale “hydrogen generator” that uses light and a two-dimensional graphene platform to boost production of the hard-to-make element.
The research also unveiled a previously unknown property of graphene. The two-dimensional chain of carbon atoms not only gives and receives electrons, but can also transfer them into another substance.
The Critical Materials Institute a DOE Energy Innovation Hub headquartered at Ames Laboratory, celebrated its first anniversary with eleven invention disclosures, all research milestones in a mission to assure the availability of rare earths and other materials critical to clean energy technologies.
The inventions include improved extractive processes, recycling techniques, and substitute materials—technologies designed to increase production and efficiency of, and reduce reliance on, the use of rare earths and other critical materials.